JPH0762218A - Room temperature curing composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition, containing a specific silicon- containing polymer, a filler and a solid catalyst, excellent in fluidity and elongation and strength of a cured product and useful as sealing materials, adhesives, etc. CONSTITUTION:This composition contains (A) an organic polymer composed of a polyoxyalkylene, obtained by polymerizing an alkylene oxide such as a 2-4C alkylene oxide with an initiator having >=3 hydroxyl groups in one molecule using a composite metallic cyanide complex such as zinc hexacyanocobaltate as a catalyst and having >=5000 number-average molecular weight and further >=0.3 silicon-containing group expressed by the formula SiXaR<1>3-a [R<1> is a 1-20C (substituted)monovalent hydrocarbon group; X is a hydrolyzable group; (a) is 1-3] based on one molecule on the average of the whole molecule, (B) a filler such as silica or carbon black and (C) a curing catalyst such as dibutyltin dilaurate. Furthermore, the component (C) is used in an amount of preferably 0.001-10 pts.wt., especially 0.01-5 pts.wt. based on 100 pts.wt. component (A).

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to room temperature curable compositions which cure in the presence of moisture.

[0002]

2. Description of the Related Art Conventionally, a method of using for a sealing material, an adhesive, etc. by utilizing a curing reaction of various compounds having a hydrolyzable silicon group at a terminal, which is known as a modified silicone resin, is often used. It is a known and industrially useful method.

It is desirable that these have appropriate viscosities at the time of compounding and at the time of use. Further, in order to exhibit the mechanical properties of the cured product, especially rubber elasticity having a high flexibility,
It is desirable to have a constant molecular weight.

[0004]

Known polymers having such a terminal hydrolyzable silicon group are disclosed, for example, in Japanese Examined Patent Publication No.
It is proposed in Japanese Patent Publication No. 5-36319, Japanese Patent Publication No. 46-17553, and the like. Particularly, those using a polyfunctional polyether compound as a main chain are disclosed in JP-A-59-230.
No. 024, etc.

However, these methods in which a polyether compound having a relatively low molecular weight is connected with a polyfunctional halogen compound to increase the molecular weight and then a hydrolyzable silicon group is introduced, the reaction is multistage. , A large amount of salt is by-produced, the molecular weight distribution (M _w / M _n ) spreads considerably, and the viscosity becomes considerably high. On the contrary, when trying to lower the viscosity of the polymer, the content of low molecular weight body However, there is a drawback that the elongation of the cured product is reduced due to the increase in the amount.
In addition, it is difficult to obtain an actually desired high molecular weight polyether compound by this method, because the polyfunctionalization makes crosslinking easy.

[0006]

DISCLOSURE OF THE INVENTION The present invention is intended to solve such a drawback, in which the main chain uses a complex metal cyanide complex (D) as a catalyst and has at least three hydroxyl groups per molecule. It is composed of a polyoxyalkylene polymer (F) having a number average molecular weight of 5000 or more obtained by polymerizing an alkylene oxide with an initiator (E), and one molecule of the silicon-containing group represented by the following general formula (1) is averaged over all molecules. Organic polymer (A) having 0.3 or more per unit, filler (B)
And a room temperature curable composition comprising a curing catalyst (C) as a main component. —SiX _a R ¹ _3-a (1) (wherein R ¹ is a substituted or unsubstituted 1 to 20 carbon atom)
Valent hydrocarbon radical. X is a hydrolyzable group. a is 1, 2 or 3. )

The polyoxyalkylene polymer (F) used as the main chain of the organic polymer (A) in the present invention uses a complex metal cyanide complex (D) as a catalyst and has at least 3 hydroxyl groups per molecule. A hydroxyl group-terminated product produced by reacting an alkylene oxide with an initiator such as a compound is preferable.

By using the complex metal cyanide complex (D), M _w / M _n is narrower than that of the polyoxyalkylene polymer produced by using the conventional alkali metal catalyst,
It is possible to obtain a polyoxyalkylene polymer (F) having a higher molecular weight and a lower viscosity. More preferably, the number of functional groups of the polyoxyalkylene polymer (F) can be arbitrarily controlled by the number of hydroxyl groups of the initiator (E), but when the molecular weights are made equal, the more polyfunctional the polyfunctional group is. The viscosity becomes low.

Further, the physical properties of the cured product after the blending of the organic polymer (A) can be freely controlled by the content of the silicon-containing group regardless of the number of functional groups of the polyoxyalkylene polymer (F). is there. Therefore, a composition using the low-viscosity organic polymer (A) having the same physical properties such as strength and elongation can be obtained. Initiator (E) used in the present invention
The number of hydroxyl groups per molecule is 3 or more, but it is preferably 3 to 6 in view of the balance of physical properties such as viscosity, strength and elongation.

The complex metal cyanide complex (D) is preferably a complex containing zinc hexacyanocobaltate as a main component, and its ether and / or alcohol complex is preferable. As the composition, those essentially described in JP-B-46-27250 can be used. As the ether, glyme, diglyme and the like are preferable, and glyme is particularly preferable from the viewpoint of handling during production of the complex. As the alcohol, t described in JP-A-4-145123 is disclosed.
-Butanol is preferred.

Examples of the polyoxyalkylene polymer (F) include polyoxyethylene compounds, polyoxypropylene compounds, polyoxybutylene compounds, polyoxyhexylene compounds, polyoxytetramethylene compounds and / or copolymers thereof. Particularly preferred polyoxyalkylene polymers are polyoxypropylene triol and polyoxypropylene tetraol.

R ¹ in the general formula (1) is a substituted or unsubstituted monovalent organic group having 1 to 20 carbon atoms, preferably an alkyl group having 8 or less carbon atoms, a phenyl group or a fluoroalkyl group. . Particularly preferably, a methyl group, an ethyl group,
Examples thereof include a propyl group, a propenyl group, a butyl group, a hexyl group, a cyclohexyl group and a phenyl group.

X in the general formula (1) is a hydrolyzable group, and examples thereof include a halogen atom, an alkoxy group, an acyloxy group, an amide group, an amino group, an aminooxy group, a ketoximate group, an acid amide group and a hydride group. is there. Of these, the hydrolyzable group having a carbon atom preferably has 6 or less carbon atoms, and particularly preferably 4 or less carbon atoms. Examples of preferable hydrolyzable groups include lower alkoxy groups having 4 or less carbon atoms, particularly methoxy group, ethoxy group, propoxy group, propenyloxy group and the like.

In the general formula (1), a is 1, 2 or 3, and particularly preferably 2 or 3.

Next, the method for producing the organic polymer (A) will be described. The organic polymer (A) in the present invention is preferably produced by introducing a silicon-containing group at the terminal of the polyoxyalkylene polymer (F) having a functional group as described below. Such compounds are liquid at room temperature,
In addition, the cured product retains flexibility even at a relatively low temperature and has desirable characteristics when used as a sealing material, an adhesive, or the like.

(A) A method of reacting a polyoxyalkylene compound having a functional group with an olefin group introduced at the terminal and a hydrosilyl compound represented by the general formula (2). HSiX _a R ¹ _3-a (2) (In the formula, R ¹ , X, and a are the same as described above.) Here, as a method for introducing an olefin group, a compound having an unsaturated group and a functional group is used. A method of reacting with a terminal hydroxyl group of an oxyalkylene compound to bond with an ether bond, an ester bond, a urethane bond, a carbonate bond, or the like, or when an alkylene oxide is polymerized, an olefin group-containing epoxy compound such as allyl glycidyl ether is added. And a method of introducing an olefin group into the side chain by copolymerization.

(B) A method of reacting a terminal of a polyoxyalkylene compound having a functional group with a compound represented by the general formula (3). R ¹ _3-a SiX _a -R ² NCO (3) (wherein R ¹ , X, and a are the same as above. R ² has 1 to 1 carbon atoms)
A divalent hydrocarbon group of 7. )

(C) After the end of the polyoxyalkylene compound having a functional group is reacted with a polyisocyanate compound such as tolylene diisocyanate to form an isocyanate group terminal, the isocyanate group is converted to silicon represented by the general formula (4). A method of reacting the W group of a compound. R ¹ _3-a -SiX _a -R ² W (4) (wherein R ¹ , R ² , X and a are the same as above. W is a hydroxyl group,
An active hydrogen-containing group selected from a carboxyl group, a mercapto group and an amino group (primary or secondary). )

(D) An olefin group is introduced at the terminal of a polyoxyalkylene compound having a functional group, and the olefin group is reacted with the mercapto group of the silicon compound represented by the general formula (4) in which W is a mercapto group. How to make.

The number of silicon-containing groups is 0.3 or more per molecule on the average of all molecules.

As the organic polymer (A) in the present invention, an organic polymer having a number average molecular weight of 5,000 to 30,000 can be used. The number average molecular weight of the organic polymer (A) is 500.
When it is lower than 0, the cured product is hard and has low elongation. When the number average molecular weight exceeds 30,000, flexibility and elongation of the cured product are not problematic, but the viscosity of the polymer itself is remarkably increased. It becomes less practical. The number average molecular weight is particularly preferably 8,000 to 300,000. Also, depending on the application, in order to control the physical properties of the cured product,
It can also be used in a mixture with a similar organic polymer using an initiator having 3 or less hydroxyl groups.

In the present invention, the curing catalyst (B) is essential for curing the organic polymer. When the curing catalyst (B) is not used, the crosslinking reaction of the hydrolyzable silicon group cannot obtain a significant reaction rate.

As the curing catalyst (B), compounds known as catalysts for the hydrolysis and condensation reaction of hydrolyzable silicon groups can be used. That is, metal salts of carboxylic acids such as alkyl titanates, organosilicon titanates, tin octylate and dibutyltin dilaurate; amine salts such as dibutylamine-2-ethylhexoate; and other acidic catalysts and Basic catalysts can be used. The curing catalyst is preferably used in an amount of 0.001 to 10 parts by weight, particularly 0.01 to 5 parts by weight, based on 100 parts by weight of the organic polymer (A). preferable.

Known fillers can be used as the filler (C) in the present invention. Specifically, fillers such as fumed silica, precipitable silica, silicic acid anhydride, silicic acid hydrate and carbon black, and carbonic acid can be used. Calcium, magnesium carbonate, diatomaceous earth, calcined clay, clay, talc, titanium oxide, bentonite, organic bentonite, ferric oxide, zinc oxide, activated zinc white, hydrogenated castor oil and filler such as shirasu balloon, asbestos, glass Fibrous fillers such as fibers and filaments can be used.

Any plasticizer may be used in the present invention. As the plasticizer, known plasticizers can be used, and specifically, phthalates such as dioctyl phthalate, dibutyl phthalate, and butylbenzyl phthalate; dioctyl adipate, isodecyl succinate, dibutyl sebacate, butyl oleate, and the like. Aliphatic carboxylic acid ester; glycol ester such as pentaerythritol ester; phosphoric acid ester such as trioctyl phosphate, tricresyl phosphate; epoxy plasticizer such as epoxidized soybean oil and benzyl epoxystearate; chlorinated paraffin etc. Alternatively, it can be used as a mixture of two or more kinds.

The composition of the present invention may further contain various known additives. As the additives, adhesion promoters such as phenol resin and epoxy resin, pigments, various antiaging agents, ultraviolet absorbers and the like can be used.

The room temperature curable resin composition of the present invention cures at room temperature in the presence of moisture, and can be used especially for elastic sealants and adhesives.

[0028]

EXAMPLES The present invention will now be described in detail with reference to examples, but the present invention is not limited to these examples. First, Reference Examples 1 and 2 show production examples of the organic polymer (A), and then Reference Examples 3 and 4 show production examples of the organic polymer used in Comparative Examples.

[Reference Example 1] Propylene oxide was polymerized with a zinc hexacyanocobaltate glyme complex using a glycerin-propylene oxide adduct having a molecular weight of 1000 as an initiator by the method described in JP-A-3-72527. Polyoxypropylene triol having an average molecular weight of 20,000 was obtained, the terminal hydroxyl group was converted to an allyl ether group, and methyldimethoxysilane was subjected to an addition reaction using chloroplatinic acid as a catalyst to give an average of 1.3 hydrolyzable silicon groups per molecule. An organic polymer (P1) having the above was obtained.

Reference Example 2 Propylene oxide was polymerized with zinc hexacyanocobaltate glyme complex using pentaerythritol as an initiator according to the method described in JP-A-3-72527 to obtain a number average molecular weight of 2000.
0 polyoxypropylene tetraol was obtained, the terminal hydroxyl group was converted to an allyl ether group, and methyldimethoxysilane was subjected to an addition reaction using chloroplatinic acid as a catalyst to have an average of 1.1 hydrolyzable silicon groups per molecule. An organic polymer (P2) was obtained.

[Reference Example 3] Propylene oxide was polymerized with a zinc hexacyanocobaltate glyme complex using a diethylene glycol-propylene oxide adduct having a molecular weight of 1000 as an initiator according to the method described in Japanese Patent Application Laid-Open No. 3-72527. Polyoxypropylene diol having an average molecular weight of 20,000 was obtained, the terminal hydroxyl group was converted into an allyl ether group, and methyldimethoxysilane was subjected to an addition reaction using chloroplatinic acid as a catalyst to give an average of 1.
Organic polymer having four hydrolyzable silicon groups (P3)
Got

[Reference Example 4] According to the method described in JP-B-60-12363, polyoxypropylene diol having a number average molecular weight of 3000 was reacted with tris (chloromethoxy) benzene, and further the terminal hydroxyl group was reacted with allyl chloride. Then, the terminal allyl ether group was formed, and then methyldimethoxysilane was subjected to an addition reaction using chloroplatinic acid as a catalyst to obtain an organic polymer (P4). The number average molecular weight of this organic polymer was 8,000.

[Examples 1 and 2 and Comparative Example 1] Reference Example 1
To 100 parts by weight of the organic polymer (P1 to P3) synthesized in 3 to 3, 160 parts by weight of calcium carbonate and 20 parts of titanium oxide.
Parts by weight, dioctyl phthalate 60 parts by weight, hydrogenated castor oil 5 parts by weight, phenolic antioxidant 1 part by weight, 3-
After adding 1 part by weight of (2-aminoethyl) aminopropylmethyldimethoxysilane and kneading, 1 part by weight of dibutyltin dilaurate was added and further kneading, and the mixture was spread into a sheet having a thickness of 2 mm and kept at a constant temperature of 50 ° C. and a humidity of 60%. It was cured in a wet tank for 7 days. The cured product was punched out with JIS No. 3 dumbbell and the physical properties were measured. 50% modulus (M ₅₀ ) (kg / cm ² ), strength at break (kg / cm ² ), elongation at break
(%), Organic polymer viscosity (25 ° C, by BH type viscometer)
(cps) is summarized in Table 1.

[0034]

[Table 1]

Comparative Example 2 The viscosity of the organic polymer (P4) synthesized in Reference Example 4 was 20000 cps (measurement conditions were the same as above).

[0036]

EFFECT OF THE INVENTION Using the double metal cyanide complex catalyst of the present invention, a polyoxyalkylene polymer obtained by polymerizing an alkylene oxide with an initiator having three or more hydroxyl groups is essentially contained in the main chain. , A room temperature curable composition having a hydrolyzable silicon group-containing organic polymer as a curing component is compared with a conventionally known polymer produced by chain extension of a polymer having a relatively low number average molecular weight, It has the effects of having excellent elongation, strength properties, and low viscosity.

Claims (3)

[Claims] 1. A number average molecular weight of 5,000 or more obtained by polymerizing an alkylene oxide in an initiator (E) having a main chain with a complex metal cyanide complex (D) as a catalyst and having at least 3 hydroxyl groups per molecule. An organic polymer (A) comprising a polyoxyalkylene polymer (F) and having at least 0.3 silicon-containing groups represented by the following general formula (1) per molecule on average per molecule, a filler (B) and A room temperature curable composition containing a curing catalyst (C) as a main component. —SiX _a R ¹ _3-a (1) (wherein R ¹ is a substituted or unsubstituted 1 to 20 carbon atom)
Valent hydrocarbon radical. X is a hydrolyzable group. a is 1, 2 or 3. ) 2. The room temperature curable composition according to claim 1, wherein the complex metal cyanide complex (D) is a complex containing zinc hexacyanocobaltate as a main component. 3. The alkylene oxide is ethylene oxide,
The room temperature curable composition according to claim 1, which is at least one selected from propylene oxide and butylene oxide.